WASHINGTON — The high cost of the US Defense Department’s weapon programs threatens national security, the head of the Pentagon’s advanced research-and-development arm said.

Arati Prabhakar, director of the Defense Advanced Research Projects Agency (DARPA), said her organization is “fundamentally rethinking” US military systems that have historically been extremely expensive.

“I think we’ve had a long history ... of using our deep pockets as a competitive advantage on the battlefield and it has been a very effective strategy,” Prabhakar said during a May 14 taping of the Defense News with Vago Muradian television show. “Now it’s starting to shoot us in the foot.”

The agency is exploring ways to make weapons more flexible and cost effective.

“Today, what we’re seeing is a degree of cost and inflexibility in our major platform systems that I believe is going to make them ineffective for the challenges we face in the future,” Prabhakar said during a conference that same day hosted by the Atlantic Council think tank.

DARPA is coming up with “powerful new approaches” to space systems, weapons, radar and navigation, and communications equipment, she said.

Being more cash-strapped could help drive Pentagon innovation in the way it does business and acquires weapons, experts say.

The high cost of weapon systems is evident in the choices and trade-offs Pentagon leadership makes, Prabhakar said.

“Those choices translate ultimately to national security capabilities,” she said. “I think we’re seeing that direct link now between cost and our future capabilities. That’s the problem that I think we have to deal with head on.”

One of the “big surprises” Prabhakar has observed is that people are looking more toward DARPA rather than pursuing incremental improvement, or upgrades, of existing systems.

“Usually budget pressure translates to incrementalism for [research and development] because people say ‘what have you done for me lately — solve today’s problems,’ ” she said.

“I’ve been really surprised to find the level of concern that we’re not on a sustainable path because of the diversity of threats and the cost of our approaches to deal with them,” she said.

This theory is the “polar opposite” to what was seen in the House Armed Services Committee markup of the Pentagon’s 2015 budget proposal, said Byron Callan, an analyst with Capital Alpha Partners.

The years, and sometimes decades, it takes to field new weapons often means that by the time it reaches the battlefield, the technology is outdated. New technologies, specifically semi-conductors, could help create new architectures that are cheaper and can get to the battlefield quicker.

“It’s this next-generation of microelectronics and microsystems that shrink our physical technologies. It’s the algorithms and the software and the information systems,” Prabhakar said.

Traditionally, when the military has downsized, leaders have invested in technologies they believe can be game changers, said retired Marine Corps Gen. James Cartwright, now with the Center for Strategic and International Studies.

Cartwright said technologies such as directed energy, cyber, electromagnetic pulse and rail guns could be those kind of game changers. ■